Silicon-based integrated circuits incorporating planar optical waveguides and light processing elements such as optical modulators, receivers, attenuators, splitters, combiners, amplifiers etc. are being developed and used in a variety of applications. Examples of such circuits, which may be referred to as silicon photonics (SiP) chips, include optical interconnects and optical routers, among others. However, conventional silicon photonics (SiP) chips cannot generate light at typical optical communication wavelengths in the 1.3 μm and 1.55 μm ranges, so that light of these wavelengths has to be coupled into a SiP chip from an external laser, typically a semiconductor laser diode (LD) emitting at the desired wavelength. What is needed is an optical transmitter assembly that has a small footprint, protects the LD from the environment and back reflections, and is configured to couple light generated by the LD directly into a SiP chip at a desired location on the chip.